1. School of Materials, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China
2. State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
3. Centre for Physical Mechanics and Biophysics, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
4. School of Physics, Sun Yat-sen University, Guangzhou 510275, China
5. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States